Standard Turbidity Research Articles

A Compact, Low-Cost, and Low-Power Turbidity Sensor for Continuous In Situ Stormwater Monitoring.

Turbidity stands as a crucial indicator for assessing water quality, and while turbidity sensors exist, their high cost prohibits their extensive use. In this paper, we introduce an innovative turbidity sensor, and it is the first low-cost turbidity sensor that is designed specifically for long-term stormwater in-field monitoring. Its low cost (USD 23.50) enables the implementation of high spatial resolution monitoring schemes. The sensor design is available under open hardware and open-source licences, and the 3D-printed sensor housing is free to modify based on different monitoring purposes and ambient conditions. The sensor was tested both in the laboratory and in the field. By testing the sensor in the lab with standard turbidity solutions, the proposed low-cost turbidity sensor demonstrated a strong linear correlation between a low-cost sensor and a commercial hand-held turbidimeter. In the field, the low-cost sensor measurements were statistically significantly correlated to a standard high-cost commercial turbidity sensor. Biofouling and drifting issues were also analysed after the sensors were deployed in the field for more than 6 months, showing that both biofouling and drift occur during monitoring. Nonetheless, in terms of maintenance requirements, the low-cost sensor exhibited similar needs compared to the GreenSpan sensor.

Effectiveness of <i>Pseudomonas Aeruginosa</i> in Destruction of Harmful Lipids in Lipidemia Patients

Pseudomonas aeruginosa is a type of harmful microorganism that belongs to a large group of Gram-negative bacteria, these bacteria can secrete many extracellular enzymes such as microbial lipase and oxidase that act on certain lipids. This study aims to activate certain enzymes of P. aeruginosa like lipase and oxidase in order to decrease high plasma triglycerides and cholesterol in lipidemia patients. Serum can also be used due to the fact that lipids are found in both serum and plasma. Five ml. of blood were collected from 100 lipidemia patients at Baghdad Teaching Hospital laboratories in Medical city, P. aeruginosa was isolated from medical wastes; cultured on bacterial media, gram stained and biochemically tested in vitro. Methods depend on inoculation of bacterial broth containing colonies of P. aeruginosa adjusted to McFarland standard turbidity with 50% of blood plasma were added, then cultures were incubated at 37°C for 6 days, activation of bacterial lipase and oxidase were done during the incubation period by addition of certain activators to the broth like glycogen liquid. The results showed that 100% of patients had cholesterol <200 mg/dl and 99% of patients had normal triglyceride level (<200mg/dl) after bacterial inoculation and activation of microbial lipase and oxidase. As conclusion, the high plasma lipids level of patients was decreased four times by P. aeruginosa may be due to the activation of microbial lipase and oxidase which could needs to future research to extract them and used them as treatment for these cases.

Challenges and Possible Solutions for Riverbank Filtration: Case Studies of Three Sites in Egypt

In response to Egypt’s escalating water scarcity and pollution, Riverbank Filtration (RBF) technology is emerging as an effective solution to enhance water quality and simplify drinking water provision. This study evaluates RBF at three sites in Upper Egypt by assessing hydrogeological conditions and water quality based on 36 parameters from 2022 to 2023. Findings indicate that RBF efficiently treats infiltrated river water, with all sites meeting turbidity and microbiological standards (Total Bacterial Count and Coliforms), achieving removal rates of approximately 90% and 99%, respectively. Despite these successes, challenges persist in reducing manganese to safe levels, with concentrations at Alsaayda site reaching 0.51 mg/L, over the drinking water safe limit of 0.4 mg/L. To address this, further post-treatment strategies are proposed to remove the excess manganese. A practical application of an Oxidizer at the Bani Murr groundwater treatment plant has demonstrated the effective removal of iron and manganese, bringing their levels down to safe drinking water standards. This case exemplifies a successful solution for iron and manganese removal. This research highlights RBF’s potential in water treatment in developing countries, while emphasizing the need for supplementary measures to manage specific contaminants.

Natural deep eutectic solvents for turbidity removal from synthetic pharmaceutical wastewater

Contamination of water resources by active pharmaceutical ingredient wastes is among major environmental concerns. To prevent major disruptions of aquatic life, an efficient and environmentally-friendly turbidity removal procedure of common contaminants such as paracetamol should be established. In this study, several natural deep eutectic solvents (NADESs) were screened to reduce the turbidity of simulated water contaminated with paracetamol below the standard turbidity limit recommended by the National Water Quality Standards for Malaysia (50 NTU). The optimal operating parameters (NADES dosage, stirring time and operating pH) were determined. Under optimized conditions, stearic acid-based NADES achieved the highest turbidity removal of 97.5 %. High coagulation performances were investigated based on molecular interaction using COSMO-RS (COnductor like Screening MOdel for Real Solvents) ?-profile and ?-potential (histogram of charge density distribution over molecular surface) and showed high affinity between the NADES compounds and paracetamol. Thus, NADESs are promising candidates for turbidity removal of paracetamol from water and are viable in further investigations for effluent treatment applications.

Morphological Features of Mosquito Larvicidal Bacillus Thuringiensis Isolated From Soil Samples of Nepal

Anopheles, Culex, and Aedes spp are the main vectors for transmitting malaria, Japanese encephalitis, lymphatics filariasis, dengue, zika, chikungunya, etc. Mosquito-borne diseases are increasing especially dengue in Nepal. Additional tools are required to decrease the disease rate. Biological control tools like Gambusia fish, Cyclopods, Bacillus thuringiensis, etc., have not been adopted and are unavailable in Nepal. The research aims to isolate mosquitocidal Bacillus thuringiensis a biological control tool from the soil samples of Nepal. Bacillus thuringiensis (Bt) was isolated from the soil samples of Nepal by the acetate selection method. The larvicidal bioassay of Bt was studied against the field-collected mosquito larvae. The isolate showing larvicidal activity was coded as Bacillus thuringiensis -14P2A (Bt-14P2A). The growth pattern of the positive control strain Bacillus thuringiensis var israelensis (Bti-IPS-82) and the test strain were studied in different types of culture media. The microscopic morphology was studied by using different staining techniques. Bt-14P2A and Bti -IPS-82 caused 100% mortality of field-collected larvae. Both the strains showed the same type of colony morphology in a standard culture media and uniform turbidity with sedimentation type of growth pattern in broth media. The strains were Gram-positive single rod-shaped of size 1.2X4.8µm in both negatively stained slides and Gram-stained slides. A slight difference in the endospore location was terminal in Bti-IPS-82 and subterminal in Bt-14P2A. The newly isolated Bt-14P2A differs from Bti-IPS-82 in arrangement and endospore location but harbors the same morphological characteristic and larvicidal activity as the positive control strain.

DASHBOARD INFORMASI KEADAAN KEKERUHAN AIR PADA AQUASCAPE MENGGUNAKAN SENSOR TURBIDITY

Aquascaping is a more artistic activity that arranges aquatic plants, rocks and wood in an aesthetically pleasing way in the aquarium thereby giving the effect of underwater gardening. The main purpose of aquascaping is to create an underwater scene with the aspect of maintaining aquatic plants and its need for energy through photosynthesis. Several factors that must be considered in the photosynthesis process include lighting as a substitute for sunlight, the level of water turbidity and the water temperature in the Aquascape. This study aims to build an Aquascape monitoring system for the Aquascape by utilizing a turbidity sensor. This study discusses how the water turbidity sensor aids work. When the water condition changes from clean to cloudy, the tool will send an email notification in the form of a solution. The water turbidity sensor reading tool is expected to be able to determine the water content by using a turbidity sensor which is relatively cheap and has good quality. The design of this water turbidity state uses the prototype method and uses the Arduino software which is used as an interface between the PC and the sensor. This research produced a prototype of a sensor reading tool to measure the turbidity of the water using NTU units that have been determined by the minister of health for water turbidity standards 5-25 NTU. Which can be used by Aquascape lovers to get information on water turbidity levels.

Indoor air bacterial load and antibiotic susceptibility pattern of isolates at Adare General Hospital in Hawassa, Ethiopia.

Air is the agent of pathogenic microbes that cause significant problems in the hospital environment. Multidrug resistance poses a major therapeutic challenge to these airborne microorganisms in hospital indoor environments. This study was conducted at Adare General Hospital in Hawassa City, Sidama, Ethiopia. A cross-sectional study was conducted. The proportional allocation method was used to select the sampled 50 rooms from the total available rooms in each category of wards and staff offices. A total of 100 indoor air samples were collected using settle plates in all units twice a day, morning (9:00-4:00 a.m.) and afternoon (3:00-4:00 p.m.). The types and number of colonies were determined in the laboratory, and the pathogenic bacteria were isolated by appropriate bacteriological techniques. Antimicrobial susceptibility testing was performed on Mueller-Hinton agar for each potentially pathogenic bacterium isolated. For each bacterium, a total of 12 antibiotics were tested using the Kirby-Bauer disk diffusion method. The test organism was adjusted to McFarland turbidity standards of 0.5. Data were entered and analyzed using the SPSS version 25 window. Descriptive analysis and one-way analysis of variance were performed. The indoor air bacterial load of Adare General Hospital was found in the range between 210 and 3,224 CFU/m3. The highest indoor air bacterial load was identified from the gynecology ward with a mean of 2,542.5CFU/m3 at p < 0.05. From 100 indoor air samples, a total of 116 bacterial pathogen isolates were obtained. Gram-positive isolates predominated at 72.4%, of which 37.1% were Staphylococcus aureus, 26.7% were coagulase-negative Staphylococci, and the rest 8.6% were Streptococcus pyogenes. The isolation of pathogenic bacteria Staphylococcus aureus and coagulase-negative Staphylococci showed a high level of resistance to ampicillin. A high bacterial load was found in the study area as compared to different indoor air biological standards. Staphylococcus aureus and coagulase-negative Staphylococci were the isolated predominant bacteria. Attention should be given to preventing and minimizing those environmental factors that favor the multiplication of bacteria in the indoor environment of a hospital for the safe health of patients, visitors, and staff.

Analisis Kualitas Air Baku dan Kualitas Air Hasil Produksi pada Instalasi Pengolahan Air (IPA) Unit Mukok PDAM Tirta Pancur Aji Kota Sanggau

The PDAM Tirta Pancur Aji Water Treatment Plant (WTP) Unit Mukok has a capacity of 10 liters/second which serves of the need clean water in the Mukok District. The water produced by the WTP Unit Mukok visually looks cloudy with impurities floating on the surface of the water. The purpose of this research is to whether the raw water rate for the parameters pH, temperature, turbidity, color and total amount of coliform complied with PP No. quality standards. 49/2010 as drinking water. The research method used is sampling and water quality testing. The results showed on the current conditions of the Mukok IPA unit, as a raw water source the Kapuas River has a quality of pH 8, temperature 28 °C, turbidity 34.9 NTU, color 224 PtCo. and a total of 25 MPN. The quality of the produced water is pH 7,3, temperature is 28° C, turbidity is 23.52 NTU, color is 4.19 PtCo, and total coliform is 10 MPN. The analysis showed that the raw water fraction does not correspond to class I in terms of turbidity and color parameters water standards PP No. 22 of 2021, the analytical results of the rate of the produced water show the turbidity and coliform parameters do not correspond to the standard of Permenkes No. 492 of 2010.

ANTIMICROBIAL PROPERTIES OF FILTERING FIBROUS MATERIALS IMPREGNATED BY AMINOMETHANESULPHONIC ACIDS

Background. The spread of a new strain of SARS-CoV-2 and the pandemic that caused it has led to huge changes around the world. So, it reminded us again about the importance of developing measures for the prevention of infections that transmitted by air droplets.&#x0D; Aim: investigation of the antimicrobial activity of aminomethanesulfonic acid (AMSA) and its derivatives (N-(2-hydroxyethyl)-(HEAMSA), N-benzyl-(BnAMSA) and N-(tert-butyl)-(t-BuAMSA)) which impregnated on filtering fibrous material and can be used for the manufacture of anti-aerosol elements of individual respiratory protection against strains of Staphylococcus aureus with different level of antibiotics resistance.&#x0D; Materials and methods. The standard method of Kirby and Bauer disks is used for the investigation of the specific activity of antimicrobial drugs. The 24-hour cultures of microorganisms that contained (1.2+0.2)x109 CFU/ml were diluted according to the turbidity standard. The results were detected after 18-20 hours of incubation at 37°C. The 0.5 cm diameter filter fibrous discs contained the following compounds: AMSA, HEAMSA, BzAMSA, t-BuAMSA and streptocide (sulfanilamide) as a reference with active compound content (Q) at a final concentration of 0.047 and 0.236 mmol/g.&#x0D; Results. All test samples with aminomethanesulfonic acids at a final concentration of 0.236 mmol/g that were applied to the filter fibrous material had a higher level of inhibition of the growth of the microorganisms than the prototype using streptocide (sulfanilamide) e against the strains of Staphylococcus aureus 2781 and Staphylococcus aureus Kunda.&#x0D; Conclusions. Samples based on HEAMSA showed the greatest antimicrobial activity against the studied strains of Staphylococcus aureus from all research samples of filter fibrous material with YAMSA. They were characterized by the maximum hydrophilicity and the minimum value of the empirical pKa function lgPow. AMSA and HEAMSA were characterized by the smallest particle sizes on the surface of lavsan fiber according to electron microscopy analysis. This provides the largest boundary of contact between the phases of these biocides in the composition of the filtering fibrous material with bio aerosols during respiratory air purification.

Study of some physical and chemical properties of drinking water in Samarra city and comparing with mineral water

This study was conducted in the city of Samarra on different samples of Samarra liquefaction and liquefaction of (S.D.I) and some mineral water samples of the most popular markets in the city, such as (nada water and alain water).&#x0D; During the study, some physical and chemical properties examination of the samples studied, such as turbidity and conductivity and the amount of soluble salts have also been some chemical properties such as the concentration of chlorine and oxygen concentration and pH measurement function.&#x0D; The study shown in the sample liquefaction of (S.D.I) is worst properties like turbidity standards and the concentration of oxygen and chlorine but they were complying in each of the pH and conductivity and the concentration of soluble salts function associated with raw water source, a river water (the Tigris River).&#x0D; It came in second place of the poor quality of water Specifications liquefaction Samarra while bottled water showed good readings of the properties studied.

Nature based-solutions for water reuse: 20 years of performance evaluation of a full-scale constructed wetland system

Water reuse is becoming an important tool in water resource management in regions with recurrent droughts and water shortages, such as the Mediterranean. However, there are still obstacles preventing the multiple application of water reuse projects, such as social acceptability and financial problems. In this context, the use of green infrastructure such as constructed wetlands in combination with conventional mechanical treatments could represent a very practical alternative. In this article, we present the evaluation of the performance and the water quality obtained by a combined system over a long period of 2 decades. The water reuse system is located in Granollers, Barcelona, Spain, and consists of 3 elements: wetland, mechanical reclamation plant and distribution network. The entire system produces >10,000 m3 annually for garden irrigation, and street and sewerage cleaning, and there are plans for a substantial increase of this water reclaimed flow in the next years. The effluent meets the water reuse standards set by the water regional authority for pH, electrical conductivity, TSS, E. coli, Legionella and Nematodes eggs, either as average or as 90th percentiles. Turbidity standard is met as average but not as 90th percentile (being 10.7 NTU, while the limit 10 NTU). The combination of the green infrastructure, represented by the wetland, and the conventional mechanical system, represented by the reclamation plant, results in excellent water quality suitable for the irrigation of public gardens and the cleaning of streets. The integration of both elements increases the reliability of the system and contributes to the social acceptance of water reuse. This work presents long-term and complete evidence at a full-scale of the contribution and benefits of nature-based solutions to sustainable water management.

Discovering hydrothermalism from Afar: In Situ methane instrumentation and change-point detection for decision-making

Seafloor hydrothermalism plays a critical role in fundamental interactions between geochemical and biological processes in the deep ocean. A significant number of hydrothermal vents are hypothesized to exist, but many of these remain undiscovered due in part to the difficulty of detecting hydrothermalism using standard sensors on rosettes towed in the water column or robotic platforms performing surveys. Here, we use in situ methane sensors to complement standard sensing technology for hydrothermalism discovery and compare sensors on a towed rosette and an autonomous underwater vehicle (AUV) during a 17 km long transect in the Northern Guaymas Basin in the Gulf of California. This transect spatially intersected with a known hydrothermally active venting site. These data show that methane signalled possible hydrothermal-activity 1.5–3 km laterally (100–150 m vertically) from a known vent. Methane as a signal for hydrothermalism performed similarly to standard turbidity sensors (plume detection 2.2–3.3 km from reference source), and more sensitively and clearly than temperature, salinity, and oxygen instruments which readily respond to physical mixing in background seawater. We additionally introduce change-point detection algorithms—streaming cross-correlation and regime identification—as a means of real-time hydrothermalism discovery and discuss related data supervision technologies that could be used in planning, executing, and monitoring explorative surveys for hydrothermalism.

Evaluation of the Microbiological Effect of Colloidal Nanosilver Solution for Root Canal Treatment.

Background: The goal of endodontic treatment, along with the preparation of the root canal and giving it a shape corresponding to the obturation technique, is the drug treatment of the canal. The aim of this study was to determine the antibacterial effect of a colloidal solution of nanosilver at its various dilutions on root canal microorganism. Materials and methods: A solution of silver nanoparticles at a concentration of 10,000 ppm (1.0%) was diluted in various concentrations (10 solutions from 1% to 0.0025%). Cultures used for research: Str. agalacticae ATCC 3984, E. faecalis ATCC 323, St. aureus ATCC 4785, C. albicans ATCC 10231. After thawing, cultures of microorganisms were introduced into a liquid nutrient medium: cerebral heart broth for bacterial cultures and Sabouraud broth for C. albicans. The cultivation was carried out at a temperature of 37 °C for 24 h. A bacterial suspension for inoculation was prepared from a microbial sediment according to a turbidity standard of 0.5 McFarland in saline. Then, 100 μL of the obtained suspension of microorganisms was inoculated by the “lawn” method using a spatula on the Muller–Hinton medium. Solutions of silver nanoparticles were introduced into wells prepared in agar with a sterile metal punch. Further incubation was carried out for 24 h at 37 °C. Results: colloidal solution of silver nanoparticles at concentrations of 1%, 0.75%, 0.5% inhibited the growth of Str. agalacticae ATCC 3984 with a growth retardation zone of 6–7 mm. The E. faecalis ATCC 29212 strain was sensitive to solutions of silver nanoparticles at concentrations of 1%, 0.75%, 0.5% with a growth inhibition zone of 6–7 mm. Strain St. aureus 4785 demonstrated sensitivity to solutions of silver nanoparticles at concentrations of 1%, 0.75%, 0.5%, 0.1%, 0.05% with a growth retardation zone of 6-8 mm. Conclusion: colloidal solutions of silver nanoparticles have antimicrobial action against gram-positive bacteria (Str.agalacticae ATCC 3984, St. aureus ATCC 4785, E. faecalis ATCC 29212) and yeast-like fungi of the genus Candida (C. albicans ATCC 10231, C. albicans 672 and C. albicans D-225M), but this action is strain-specific and depends on the concentration of the solution.

INHIBITORY POWER OF PROBIOTICS DRINKS ON THE STREPTOCOCCUS MUTANS GROWTH

Background: Streptococcus mutans is an oral cavity bacteria that is dominantly found. The acidogenic nature of bacteria can affect the damage to the physical and biochemical structures of dental biofilms. Streptococcus mutans growth becomes important to control. One way to control its growth is through the use of probiotic bacteria available in processed foods. The objective of this study is to investigate the effect of probiotic drinks against the Streptococcus mutans mutans. Method: This study is experimental research with a posttest-only group design, using two test groups. Streptococcus mutans suspension with McFarland turbidity standard of 0.5 in MRS Agar medium was placed on a paper disc that had been soaked in aqua dest (control group) or probiotic drink (treatment group) for ± 20 minutes and then incubated for 48 hours at 37oC. Each group was replicated 16 times. After incubation, the diameter of the Streptococcus mutans growth inhibition zone formed was measured using a caliper.Result: The control group did not show an inhibitory zone, while the treatment group resulted in a mean diameter inhibition zone of 1.18 mm. The Mann Whitney test proved that the treatment group had a significantly higher diameter of the inhibition zone compared to the control one (p=0.000).Conclusion: Probiotic drink had an inhibitory power on the Streptococcus mutans growth

Implementation and Calibration of an IoT Light Attenuation Turbidity Sensor

Turbidity is an important characteristic of water quality that can indicate the presence of undesirable suspended particulate matter. Having access to an inexpensive and effective turbidity sensor unlocks numerous Internet of Things (IoT) possibilities for remote environmental monitoring. Optical light attenuation turbidity sensors operate on the premise of detecting signal degradation from a light source due to scattering from particles in a solution. This approach is technologically unpretentious and only requires a handful of inexpensive electronic components to construct. However, while this method is touted as “simple”, a significant challenge lies in sensor calibration. That is, converting an analogue signal into a meaningful and accurate digital reading in a known turbidity measurement standard (e.g., Nephelometric Turbidity Units (NTU)). This paper presents an IoT light attenuation turbidity sensor design and explores the calibration process to determine the sensor's range and accuracy. Sensor calibration is undertaken using Formazin turbidity standards and is cross-checked against a commercial turbidimeter. We provide a step-by-step procedure for determining the correct signal strength to use and a functional form for the sensor response to the Formazin standard. Finally, we specify an estimate of the accuracy of the sensor and suggest the next steps in the proposed turbidity sensor's development. Results indicate that the sensor achieves within 2%-10% of accuracy at higher ranges (100–4000 NTU), but its performance becomes significantly less reliable in low NTU ranges (< 100 NTU) where the error rate increases to 26%. The turbidity sensor is used as part of an IoT remote aquatic environmental monitoring platform.

Tranexamic Acid in Combination With Vancomycin or Gentamicin Has a Synergistic Effect Against Staphylococci.

BackgroundTranexamic acid (TXA) is an antifibrinolytic agent applied in orthopedic surgery and has been proven to reduce post-surgery infection rates. We previously showed that TXA also had an additional direct antimicrobial effect against planktonic bacteria. Therefore, we aimed to evaluate whether it has a synergistic effect if in combination with antibiotics.Materials and MethodsThree ATCC and seven clinical strains of staphylococci were tested against serial dilutions of vancomycin and gentamicin alone and in combination with TXA at 10 and 50 mg/ml. The standardized microtiter plate method was used. Minimal inhibitory concentrations (MICs) were calculated by standard visualization of well turbidity (the lowest concentration at which complete absence of well bacterial growth was observed by the researcher) and using the automated method (the lowest concentration at which ≥80% reduction in well bacterial growth was measured using a spectrophotometer).ResultsTranexamic acid-10 mg/ml reduced the MIC of vancomycin and gentamicin with both the standard method (V: 1-fold dilution, G: 4-fold dilutions) and the automated turbidity method (vancomycin: 8-fold dilutions, gentamicin: 8-fold dilutions). TXA-50 mg/ml reduced the MIC of gentamicin with both the standard turbidity method (6-fold dilutions) and the automated turbidity method (1-fold dilutions). In contrast, for vancomycin, the MIC remained the same using the standard method, and only a 1-fold dilution was reduced using the automated method.ConclusionOurs was a proof-of-concept study in which we suggest that TXA may have a synergistic effect when combined with both vancomycin and gentamicin, especially at 10 mg/ml, which is the concentration generally used in clinical practice.

Intralaboratory testing of the PCR protocol for molecular genetic identification of bacteria of the genus Staphylococcus spp

The results of optimization of the Staphylococcus spp. identification protocol by polymerase chain reaction with agarose gel detection and approbation of the protocol with wild strains selected from dogs are presented. Determination of the parameters of specificity and sensitivity of the method was performed on museum strains of cocci S. epidermidis ATCC 14990, S. aureus ATCC 25923, S. aureus subsp. aureus UKM B-918, S. pneumoniae ATCC 49619 and E. faecalis ATCC 194433. DNA extraction was performed using the IndiSpin Pathogen Kit. The ready PCR mix NEB OneTaq® 2X Master Mix with Standard Buffer was used to prepare the reaction mixture. Primers targeted to the tuf gene region using an amplification product of 370 bp were used for the study. The reaction results were recorded in a 2% agronomic gel with the addition of ethidium bromide at a concentration of 0.5%. The optimal annealing temperature was determined by the temperature gradient method. In a study of the specificity of the method, three museum strains of staphylococci were identified as positive, while strains of other cocci did not give reaction products. The sensitivity study of the method was to detect the amplification product in seven dilutions of bacterial suspension that meet McFarland turbidity standards, the lowest concentration was further diluted 10, 100 and 1,000 times. The last dilution, which showed the presence of the amplification product corresponds to 2×106 CFU in 200 μl of saline used for DNA isolation. PCR protocol was tested on wild staphylococcal strains. Ear and nasal swabs of dogs, as well as washes from the transfer cage were selected for the study. The primary inoculation of the material was carried out on mannitol salt agar, on this medium only the growth of halophilic microorganisms is possible. Growth was found on 17 Petri dishes. The PCR washings of these cups indicated the presence of staphylococci in the test materials. The results of in-laboratory PCR testing indicate that the primer we used gives high indicators of specificity and sensitivity. Our tested technique can be used to confirm the presence of Staphylococcus spp. bacteria in the primary culture of smears taken from dogs. Key words: PCR, tuf gene, approbation of primers, optimization of primers, dog microflora, Staphylococcus spp.

INVESTIGATING SENSITIVITY OF TYPICAL STRAINS AND CLINICAL ISOLATES OF STAPHYLOCOCCUS SPP. TO DECASAN, CHLORHEXIDINE AND IODOPHERE BY DISCA-DIFFUSION METHOD EUCAST

Antibiotic resistance is a global challenge, whose emergence is associated with the irrational and uncontrolled use of antimicrobial drugs, or the use of antibiotics to prevent local and systemic complications during the surgical operations. Therefore, the number of failed outcomes of the planned treatment of infectious and inflammatory processes with antibiotics has increased. Given this fact, it is important to study the potential of antiseptic drugs, which usually do not cause the microorganism resistance and thus are more advantageous over antibiotics. Objective of this study is to compare the effects of antiseptics Decasan, Chlorhexidine and Iodoform on clinical and typical strains of microorganisms using the disco-diffusion method according to the EUCAST. Materials and methods: Typical strains of Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 14990 were used as the studied cultures of microorganisms. Clinical isolates of the microorganisms Staphylococcus aureus, Staphylococcus epidermidis were collected from patients with postextraction complications, who took treatment at surgical departments of Poltava. Identification of isolated cultures was performed using an automatic bacteriological analyzer Vitec-2 compact bioMarieux (France). The antibacterial effect of antiseptic drugs Dekasan, Chlorhexidine, Iodoform was studied. Given that iodoform is poorly soluble in water, we used its 5% alcohol solution, which was prepared ex tempore. The susceptibility of the studied strains to antiseptics was determined by disco-diffusion method according to the EUCAST committee. The determination was performed by using Mueller-Hinton medium (HIMEDIA, India) with standard sterile disks, which were not impregnated (HIMEDIA, India). Then we impregnated them with solutions of Decasan, Chlorhexidine and 5% alcohol solution of iodoform. We used a microbial inoculum equivalent to according to the McFarland turbidity standard. Prepared Petri dishes containing impregnated paper disks were incubated overnight at 35-36 °C, after which the results were determined. Results and discussion: The study has shown that the antiseptic Decasan has a greater antistaphylococcal effect on typical strains and clinical isolates of staphylococci compared to other antiseptics, which are often used in dentistry. The lowest antistaphylococcal effect on the studied microorganisms has been found by applying 5% alcohol solution of iodoform, Chlorhexidine has demonstrated the moderate effect on the strains under the study.

Preparation and Use of Cellular Reagents: A Low-resource Molecular Biology Reagent Platform.

Protein reagents are indispensable for most molecular and synthetic biology procedures. Most conventional protocols rely on highly purified protein reagents that require considerable expertise, time, and infrastructure to produce. In consequence, most proteins are acquired from commercial sources, reagent expense is often high, and accessibility may be hampered by shipping delays, customs barriers, geopolitical constraints, and the need for a constant cold chain. Such limitations to the widespread availability of protein reagents, in turn, limit the expansion and adoption of molecular biology methods in research, education, and technology development and application. Here, we describe protocols for producing a low-resource and locally sustainable reagent delivery system, termed "cellular reagents," in which bacteria engineered to overexpress proteins of interest are dried and can then be used directly as reagent packets in numerous molecular biology reactions, without the need for protein purification or a constant cold chain. As an example of their application, we describe the execution of polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) using cellular reagents, detailing how to replace pure protein reagents with optimal amounts of rehydrated cellular reagents. We additionally describe a do-it-yourself fluorescence visualization device for using these cellular reagents in common molecular biology applications. The methods presented in this article can be used for low-cost, on-site production of commonly used molecular biology reagents (including DNA and RNA polymerases, reverse transcriptases, and ligases) with minimal instrumentation and expertise, and without the need for protein purification. Consequently, these methods should generally make molecular biology reagents more affordable and accessible. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Preparation of cellular reagents Alternate Protocol 1: Preparation of lyophilized cellular reagents Alternate Protocol 2: Evaluation of bacterial culture growth via comparison to McFarland turbidity standards Support Protocol 1: SDS-PAGE for protein expression analysis of cellular reagents Basic Protocol 2: Using Taq DNA polymerase cellular reagents for PCR Basic Protocol 3: Using Br512 DNA polymerase cellular reagents for loop-mediated isothermal amplification (LAMP) Support Protocol 2: Building a fluorescence visualization device.

АНТИБАКТЕРИАЛЬНОЕ ДЕЙСТВИЕ НАНОЧАСТИЦ СЕРЕБРА

Objective. To determine the minimum inhibitory concentration of Ag nanoparticles in relation to clinical pathogenic strains of microorganisms. Methods. The minimum inhibitory concentration of Ag nanoparticles, obtained by metal vapor synthesis was studied on six strains of pathogenic bacteria, including representatives of gram-positive and gram-negative groups. The microbiological analyzer Vitek 2 Compact was used to identify each strain and to determine the antibiogram. The metal nanoparticles used in the study were synthesized by the method of metalvapor synthesis. Ag nanoparticles were studied by transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy (XPS) methods. Determination of the minimum inhibitory concentration was performed by the method of serial dilution using sterile 96-well plates with using the tests of positive and negative control. The concentration of microorganisms was controlled by the turbidity standard. Results. All pathogenic strains of bacteria used in the study were characterized by pronounced polyantibiotic resistance, and the percentage of antibiotics against which the strain was resistant ranged from 12.5 to 93.3%. The minimum inhibitory concentration of silver nanoparticles ranged from 7.81 to 31.25 μg/ml, depending on the type of microorganism. Gram-positive microorganisms, in contrast to gram-negative ones, were characterized by lower values of the minimum inhibitory concentration. The data of transmission electron and X-ray photoelectron spectroscopy showed that the size of the studied nanoparticles is in the range of 2-15 nm. Conclusion. Silver nanoparticles (2-15 nm in size) have antimicrobial action against clinically significant, polyantibiotic-resistant strains of microorganisms. The minimum inhibitory concentration of silver nanoparticles, depending on the strain of the microorganism, varies from 7.81 to 31.25 μg/ml. Silver nanoparticles have an inhibitory impact on microorganisms and to a greater extent inhibit the growth of gram-positive versus gram-negative. The obtained materials based on silver nanoparticles represent an effective alternative to the currently used antibacterial drugs. What this paper adds The quantitative indices of the antibacterial action of silver nanoparticles have been firstly studied on pathogenic polyantibioticresistant strains of microorganisms The impact of the antibacterial resistance of bacteria does not affect the degree of antimicrobial action of these nanoparticles has been demonstrated Determination of the minimum inhibitory concentration of silver nanoparticles is considered to be a significant step in the development of a scientifically based method of using this class of substances in surgery